Anyone who uses a smartphone knows the importance of carrying a backup power bank. But given the overwhelming number of options on Amazon, you might feel overwhelmed, understandably. Besides the various charging specs, ports, and even cables you have to consider, there are a ton of competing brands. It’s common to see products from Anker, Mophie, and MyCharge, but how do you know which ones deliver on their promises? Is it worth saving a few bucks if a battery pack’s performance is lacking?

We decided to do the legwork for you, acquiring a wide range of power banks from different manufacturers, some offering unique features. We then spent weeks testing the packs (read about our testing process in detail below).

While we’ve made some top picks, be sure to read through each review, linked to at the bottom of this page, to help you find the best battery pack for your needs. (You might also be interested in our our roundup of USB car chargers if you spend a lot of time in a vehicle.)

Best overall power bank

The Powerstation Plus demonstrated greater efficiency than any other battery pack we've tested. This alone helps counter some of its less appealing features.

The Mophie Powerstation Plus XL is light, easy to toss into a bag, and incredibly efficient. It’s also one of the the most expensive packs in this roundup, at $99.95. But with a 93.41 percent efficiency rating, you’re getting your money’s worth out of this pack. Combine that with a built-in charging cable with multiple tips, and you have a winner. We did have an issue with recharge time, but overall this pack is the one to beat. (Read our full review).

Most portable power bank

A great battery pack for travelers, the Presto PBT10 is lightweight, capable, and efficient—at a price you won't think twice about.

Tronsmart’s Presto PBT10 is small but packs a punch. Its 10,000mAh battery is more than enough to charge a smartphone a few times without needing to be recharged itself. With an efficiency rating over 90 percent, and a price point of just $21, it’s our top pick for anyone looking for a battery pack to travel with.

Best power bank for road warriors

Mentioned in this article

It's on the heavier side, but this battery pack offers the versatility and power to make it a handy companion for keeping devices of all types ready for action.

The DBPower Q100 Portable Energy Storage Battery isn’t for those who just frequently travel, that’s where the Tronsmart Presto PBT10 excels. Instead, the Q100 is for those who frequently travel and find themselves in areas without easy access to power in general. The Q100 has an AC outlet, two USB ports, and charges in a scant 3.5 hours for a device with a 26,400mAh battery.

Best USB-C power bank

Between its capacity, recharge time, charging capabilities, USB-C, and the wide range of devices it can charge, the Anker Powercore+ 26800 PD is well worth its $110 price.

Yes, it’s big and bulky. But being able to quickly top off your phone while trekking through The Legend of Zelda: Breath of the Wild on the Nintendo Switch simultaneously is worth the added weight and the price. (Read our full review.)

How we tested

Determining whether a power bank lives up to a company’s promise entails more than simply connecting it to a phone and charging. Testing battery packs is done over weeks, not days, and requires extra equipment in order to ensure the batteries work as expected.

Upon receiving each battery pack, it was fully charged using indicator lights as a means to track charge level.

Using the DROK load tester to drain the pack of power, we were able to test against a battery’s stated maximum current, and verify that proper shutdown mechanisms were in place should something go wrong during a charging session (such as a device drawing over the maximum amps).

By using the PortaPow Power Monitor, we were able to monitor volts and amps, total power throughput, and total amount of time to deplete a battery from full to empty.

Next, we recharged the battery, this time using the PortaPow to track it throughout and the total amount of time to achieve a full battery, based on watt-hours.

There are some hiccups using this method, however. We had to use a GoPro camera to track each battery through its charge cycle, due to the PortaPow monitor continuing to collect data after the battery was fully charged (trickle charging is normal, and unfortunately interferes with our testing).

If a battery was capable of charging through USB-C, we used that instead of Micro-USB.

We then connected each battery to a Pixel XL and LG G5 to ensure that the devices registered the expected fast-charging output for each respective device.

Power source and cables

All of our tests were conducted using the same wall adapter and, when possible, USB-C or Micro-USB cable. This was done to eliminate any discrepancies with wall adapters and cable throughput.

What to look for in a portable power bank

Without fancy testing equipment, you never truly know if you’re getting what you paid for with a battery pack. Vendors, especially in Amazon listings, like to throw around a lot of terms and certifications.

Here are a few tips to help you make a decision:

For those with a compatible device, make sure the battery pack is Quick Charge 2.0, 3.0, or PD certified. Depending on your smartphone, this can make a big difference in performance. If you own a QC 2.0 device, however, ask yourself if paying extra for a QC 3.0 capable pack is worth it.

Don’t put 100 percent confidence in a company’s claims of a pack being able to charge, say, a Galaxy S8 or iPhone X six times over. Battery capacity and efficiency varies based on a number of factors. Read this Macworld report on USB-C packs to learn more about batteries and capacity.

Look at the specs of the battery, and ensure that its input isn’t limited to slow charging such as 5V/1A. The faster the input, the faster your battery pack rechargers, the faster you’re ready to hit the road.

All of our power bank reviews

Click on the links below to read the full reviews of all the products we tested for this roundup. We will continue to review and update this article as we test more battery packs.

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Cons

Take your standard wall adapter, with a single USB port for charging your smartphone, add two additional ports, a power button, indicator lights, and an internal battery, and you’ll wind up with Anker’s PowerCore Fusion 5000.